Pen



FIG. 1 is a perspective view of a pen;

FIG. 2 is a perspective view in opened position thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side view thereof; and

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a top plan elevational view thereof; and

FIG. 8 is a bottom plan view thereof;

FIG. 9 is a front view in opened position thereof; and,

FIG. 10 is a right side view in opened position thereof.

The ornamental design for a pen, as shown and described.